Clinical Measurement of Maximum Mouth Opening in Children of Kolkata and Its Relation with Different Facial Types

Introduction: Maximal opening of mouth is described as the greatest distance between incisal edge of maxillary central incisor to the incisal edge of mandibular central incisor, when the mouth is opened as wide as possible painlessly or as the inter incisal distance plus the overbite. Clinical measurement of normal range of Maximum Mouth Opening (MMO) in children is an important diagnostic criterion for evaluation of stomatognathic system, especially for those with temporomandibular and neurogenic dysfunctions. Aim: To determine the correlation of maximal mouth opening with age, sex, height, body weight and different facial types. Materials and Methods: The study was a cross-sectional study which was conducted on 434 children, who were randomly divided into three groups based on their age: Group I-children of age 6 to 8 years, Group II-children of age 8.1 to 10 years, Group III-children of age 10.1 to 12 years. For each child, the examiner took three readings of MMO in millimeters (mm) and the mean of the three readings was considered. Age, sex, standing height, body weight and facial type of each child were also recorded simultaneously. Pearson correlation was used to determine the relationship between the different parameters. p-value <0.05 was the bench mark for statistical significance in the analysis. Descriptive and inferential analysis was done for the data using SPSS version 20.0. (SPSS 20, inc.; Chicago). Results: The estimated average MMO measured for girls and boys in the age range of 6-8 years, with a total sample size of 139, was 41.14 +/- 4.29 mm and 42.16 +/- 3.98mm respectively in euryprosopic face type. In leptoproscopic face type, it was 42.12 +/- 4.54mm and 43.76 +/- 3.80 mm in girls and boys respectively. In mesoproscopic face type, MMO measured was 41.77 +/- 4.09mm and 42.51 +/- 3.95 mm in girls and boys respectively. The estimated average MMO measured for girls and boys in the age range of 8.1-10 years, with a total sample size of 143, was 44.42 +/- 4.69mm and 43.30 +/- 4.11 mm in euryprosopic face type. In leptoproscopic face type, it was 43.02 +/- 3.92mm and 46.29 +/- 3.09mm in girls and boys respectively. In mesoproscopic face type, MMO measured was 42.50 +/- 4.32 and 42.80 +/- 5.16 mm in girls and boys respectively. The estimated average MMO measured for girls and boys in the age range of 10.1-12 years, with a total sample size of 152, was 44.63 +/- 5.28 mm and 45.80 +/- 5.18 mm respectively in euryprosopic face type. In leptoproscopic face type, it was 45.76 +/- 4.98 mm and 46.28 +/- 4.68 mm in girls and boys respectively. In mesoproscopic face type, MMO measured was 45.32 +/- 5.80 mm and 46.03 +/- 5.86 mm in girls and boys respectively. Conclusion: There was a significant difference in MMO between males and females; with males having higher values in all age groups. MMO is seen to increase with age in a statistically significant manner. Significantly increased value of MMO was observed in leptoproscopic face type in comparison to euryproscopic and mesoproscopic face type for each age group.